LONGITUDINAL RESEARCH: CHARACTERISTICS, ADVANTAGES AND EXAMPLES - SCIENCE - 2025

A longitudinal investigation is one where continuous or repeated measurements of a given phenomenon are carried out over long periods of time. Often times, this type of research can take years or decades. They are generally observational in nature, and can collect both quantitative and qualitative data.

For example, countries such as Sweden, Norway, and the United States have conducted periodic population censuses for more than two centuries (1749, 1769, and 1970, respectively). In addition, since the 1970s these studies have proliferated in the social and behavioral sciences, among other disciplines.

Thus, the scientific community recognizes its value and many areas of knowledge give evidence of its usefulness. One of them is in the field of medicine. They are often used to assess the relationship between risk factors and the development of disease. They can also measure the results of different treatments.

On the other hand, its true value lies in its ability to answer questions that cannot be addressed with another type of design. A longitudinal study, in the opinion of many experts, is ideal for establishing the temporal order, measuring changes, and making the robust causal interpretations required in the scientific method.

characteristics

The characteristics of a longitudinal investigation are evident when compared with its counterpart: cross-sectional studies. Data collection on one or more variables, in the latter, occurs in a single moment.

In contrast, in longitudinal designs the data is collected in two or more moments. This allows you to measure the changes. Also, in many cases they can provide some kind of explanation for these.

Likewise, a longitudinal study allows the accumulation of a much larger number of variables, and can be extended to a much broader area of ​​knowledge than would be possible in a cross-sectional study. This is because the collection of information can be distributed at various times.

In general, four types of longitudinal research designs can be distinguished. The first of them measures the variables in the entire population in each period of the study.

Samples are taken for the other designs. This sample can be the same or different each time. A final design is to replace some individuals.

Advantages and disadvantages

Advantage

Longitudinal research provides the benefits of having extended time frames. Among its many advantages is its usefulness to establish causal relationships. It is also useful for making reliable inferences. This is possible because it allows to separate real tendencies from chance occurrences.

On the other hand, it is appropriate for charting the growth and development of many phenomena. It also shows how the changing properties of people fit into systemic change, and allows trapping the dynamics of these changes, the flows to and from particular states and the transitions between states.

Also, through longitudinal research, data are collected contemporaneously rather than retrospectively. With this, false or selective memory problems are avoided.

Also, these studies offer a comprehensive and comprehensive coverage of a wide range of variables, both initial and emerging. This includes addressing individual specific effects and population heterogeneity.

Finally, longitudinal research reduces the sampling error. The latter occurs because the study remains with the same sample over time. Then, based on its results, clear recommendations can be made in cases where intervention is required.

Disadvantages

Despite the benefits it offers, longitudinal research also has some weaknesses. One of the most important is the time it takes to have concrete results. In addition to this, the mortality problems of the sample increase over time and decrease the initial representativeness.

On the other hand, there are the effects of control. For example, repeated interviews with the same sample may have an impact on their behavior. These intervening effects mitigate the initial investigation plan.

Two other big problems are data participation and analysis. With regard to participation, it must be ensured, as this type of study involves repeated contact. In reference to the data, these are rich at the individual level, although they are typically complex to analyze.

Examples

Relationship between daily activities and successful aging

In 2003, Verena H. Menec presented a 6-year longitudinal study. Their objective was to examine the relationship between daily activities and indicators of successful aging.

Thus, the study evaluated activity in 1990 and function, well-being, and mortality in 1996. Well-being was measured in terms of life satisfaction and happiness. For its part, function was defined in terms of a composite measure that combines physical and cognitive function.

In general, social and productive activities were positively related to all three indicators. However, the loneliest activities (like reading) were associated only with happiness.

Longitudinal research on fingerprint recognition

Human fingerprint identification is based on the fundamental premise that the ridge patterns of different fingers are different, but it is also assumed that the fingerprint pattern does not change over time (persistence). However, the latter is a general belief based on only a few case studies.

In this study, conducted by Yoon and Jain (2015), fingerprint match scores were analyzed using multilevel statistical models. Among the covariates studied are the time interval between two fingerprints compared to the age of the subject and the quality of the image.

For the sample, individuals with at least five records of 10 impressions in a minimum period of 5 years were taken. The results showed that the scores tend to decrease significantly as the time interval increases. Also, the recognition accuracy becomes substantially great if the image is of poor quality.

Association between doctor burnout and changes in professional work

The aim of the researchers was to evaluate the relationship between burnout and professional satisfaction with changes in the professional effort of physicians.

For this, administrative records of the Mayo Clinic from 2008 to 2014 were used. Likewise, exhaustion and satisfaction were evaluated through surveys.

The results showed that burnout and decreased satisfaction were strongly associated with actual reductions in physician professional work effort.

References

1. Caruana, EJ; Roman, M.; Hernández-Sánchez, J. and Solli, P. (2015). Longitudinal studies. Journal of Thoracic Disease, 7 (11), pp. E537 – E540.
2. Ávila Baray, HL (2006). Introduction to Research Methodology. Taken from eumed.net.
3. Menard, S. (2002). Longitudinal Research, Vol. 76. SAGE: Thousand Oaks.
4. Cohen, L.; Manion, L. and Morrison, K. (2017). Research Methods in Education. London: Routledge.
5. Menard, S. (2007). Introduction: Longitudinal Research: Design and Analysis. In S. Menard (Editor), Handbook of Longitudinal Research: Design, Measurement, and Analysis, pp. 3-12. New York: Elsevier.
6. Verena H. Menec; The Relation Between Everyday Activities and Successful Aging: A 6-Year Longitudinal Study, The Journals of Gerontology: Series B, Volume 58, Issue 2, 1 March 2003, Pages S74 – S82.
7. Yoon, S. and Jain, A. K (2015). Longitudinal study of fingerprint recognition.

   Proceedings of the National Academy of Sciences, Vol. 112, No. 28, pp. 8555-8560.

8. Shanafelt, TD et al. (2016). Longitudinal Study Evaluating the Association Between Physician Burnout and Changes in Professional Work Effort. Mayo Clinic Proceedings, Vol. 91, No. 4, pp. 422-431.